1. Field of the Invention
The present invention relates to a method for changing scale of touch-based measurement equipment, and more particularly to a method capable of realizing stepwise scale adjustment of touch-based measurement equipment with one single finger.
2. Description of the Related Art
Measurement equipment, such as oscilloscope, spectrum analyzer and the like, serves to display waveforms of testing signals. Given the oscilloscope as an example, the values of a displayed waveform on the oscilloscope in vertical and horizontal axes respectively represent magnitude and time of the waveform. To precisely acquire the values in the vertical and horizontal axes or prevent the displayed waveform from going out of bound vertically or horizontally, frequently adjusting stepwise scales, such as 1×, 10×, 100×, 1000× and the like, becomes essential. The most traditional way of adjusting scale is to adjust scale through a knob. After a touch screen is applied to the foregoing measurement equipment, touch-based scale adjustment is also supported and can be classified into two types as follows.
One type of touch-based scale adjustment is performed by using two-finger pinch gesture and is advantageous in its intuitive operation. However, a distance between the two fingers in the pinch gesture is hard to be controlled precisely such that stepwise scale adjustment is not easy to be implemented.
The other type of touch-based scale adjustment is performed by touching virtual buttons on the touch screen. With reference to FIG. 9, a conventional touch screen 70 of an oscilloscope has a waveform area 71 for displaying a waveform of a testing signal. The waveform area 71 has multiple virtual buttons 72, 73 located on a lower portion below the waveform area 71. When one of the virtual buttons 72 is touched, a popup window for horizontal scale adjustment 720 is displayed on the waveform area 71 as shown in FIG. 10. The popup window for horizontal scale adjustment 720 has a track bar 721 that is horizontally movable for users to perform a stepwise scale adjustment in the horizontal direction (time) upon pressing and dragging it to the right or to the left. When the other virtual button 73 is touched, a popup window for vertical scale adjustment 730 is displayed on the waveform area 71 as shown in FIG. 11. The popup window for vertical scale adjustment 730 has at least one track bar 731 that is vertically movable for users to perform a stepwise scale adjustment in the vertical direction (magnitude) upon pressing and dragging it to the top or to the bottom.
Although the foregoing virtual buttons 72, 73 can be used for scale adjustment, the issue of operational inconvenience still exists. To ensure better view for observing the waveform area 71, the virtual buttons 72, 73 below the waveform area 71 and the popup windows 720, 730 should be reduced in size as much as possible. Due to the size reduction, the virtual buttons 72, 73 and the track bars 721, 731 in the popup windows 720, 730 that are relatively smaller give rise to difficulty in operation and an unfriendly users' interface for scale adjustment.